Advice needed

Our horse is only 7-8 years old, has uveitis, cataracts, and is mostly blind.

I became disabled and divorced and my ex husband no longer wishes to pay for the horse.

I don’t think I can reasonably afford all the expenses that come with him due to my disability costing thousands in medical bills.

Given his mostly low vision …rehoming feels grim. Euthanizing seems like maybe a kindness though he is young and thriving at his current barn.

Any advice possible would be appreciated.